Bitcoin Pioneer Nick Szabo Urges Users to 'Run Knots' and Skip Core v30

Nick Szabo, the computer scientist, cryptographer, and legal scholar famed for introducing the concept of “smart contracts,” is jumping into the Knots vs. Core debate. Szabo cautions that this change effectively invites more non-financial—and potentially shady—data to be etched onto the blockchain for everyone to see.

Szabo’s Warning Ignites Debate Over Bitcoin Core v30

Nick Szabo has resurfaced on social media, and he’s not staying quiet about the ongoing Knots vs. Core debate. In recent times, a growing number of users are opting to run Bitcoin Knots nodes instead of Bitcoin Core v30, favoring Knots for its tighter user control, advanced spam filters, and flexible policy settings—features Core v30 recently stripped away in the name of neutrality and cleaner code.

Szabo weighed in on Oct. 1, dropping his thoughts in a pointed X thread. “It’s a very well-publicized increase in the OP_RETURN allowance that very publicly invites more non-financial data onto Bitcoin,” he wrote. “Even though apps can already put data in other parts of Bitcoin, this increase sends a signal inviting more such data. Without adding safeguards to allow archival node operators to non-disruptively delete illegal content for which they will often be held criminally liable.”

Need More Info on This Issue? Read More Here: Decoding OP_RETURN in Bitcoin and What’s the Big Deal?

Essentially, Core v30 scrapped the long-standing 80-byte cap on OP_RETURN, opening the door to unlimited data storage inside transactions, while also deprecating several mempool filtering tools. That combo move has Knots supporters crying foul—arguing it could unleash a torrent of non-financial data onto Bitcoin’s blockchain, potentially clogging the network and even embedding illegal material. Core advocates counter that the 80-byte OP_RETURN cap was never a real safeguard anyway—insisting that, cap or not, determined users could always find ways to slip non-financial data onto the blockchain.

Following his Oct. 1 remarks, Szabo doubled down a week later, urging users to take matters into their own hands—at least for now. “As a (hopefully) temporary measure, run Knots. I strongly recommend not upgrading to Core v30,” he advised on Oct. 8, signaling clear skepticism toward the latest Core release. While many agreed, several critics weren’t exactly thrilled with Szabo’s commentary, taking issue with his stance and sparking a fresh wave of debate across the Bitcoin community.

“I recommend learning about Knots before deciding to run it,” software developer Jameson Lopp replied to Szabo. “Meh this legal take is gibberish, someone told me you even studied law,” Thomas Rossi responded. “Judges and regulators also consider feasibility and enforceability of their decisions. It’s not a coincidence that nothing has happened about the ‘bad bytes’ which already are in the blockchain,” Rossi added.

On the other hand, others agreed with Szabo. “Or just stay on v29, also an option for people who may be scared about some other changes Knots may have. Either way, I also advise against upgrading to v30,” the X account Timón Lee said. “Has any Bitcoin Core Dev asked for a pause to evaluate before going over the cliff?” another account asked.

As the Knots vs. Core divide deepens, Szabo’s warnings have fueled the long-standing tensions between Bitcoin’s financial purists and developers reportedly prioritizing simplicity and neutrality. Fact is, many are choosing sides over this matter.